I occasionally get asked to build unusual musical instruments. I’m always up for a challenge and when local musician Ed Mikenas contacted me with the idea for creating a Monochord in C based on the overtone series for the fundamental C, I obviously could not say no. He wanted a plucked instrument that was acoustically able to provide the fundamental (in this case C2) plus octaves of that note (C3, C4, C5 and C6) plus all the overtones of that fundamental played as individual strings.
There are a lot of versions of Monochords out there which seem to be more popular in Europe then here. These Monochords are based on a variety of fundamentals but generally have more strings in unison with less attempts at giving you overtones. There are some Monochords which add some of those overtones by placing individual chessman bridges on some of the strings of a rectangular instrument giving you those higher pitches and shorter vibrating lengths. The following video is an example of this type of monochord.
I played with this idea but couldn’t really come up with an instrument that was rectangular that would give me the quality of tone desired with such a range of pitches and vibrating lengths (C2 to C6). In laying out the vibrating lengths, visually it suggested more of a bowed psaltery type layout. I had just completed the design of a baritone bowed psaltery (see photo below) which ultimately influenced the design of the Monochord. What came out of that synthesis was an instrument with a 2 3/4″ thick body, 36″ in length and 9 1/2″ wide. The instrument pictured at the top of this post has cherry back and sides, a sitka spruce soundboard with ebony bridge and accents. There are 16 strings spaced 3/8″ apart.